1. Field of the Invention
The present invention relates to an audio signal processing technology, and more particularly, to an improved method and apparatus for automatically compensating a tone color without an additional key manipulation by a user.
2. Description of the Background Art
FIG. 1 is a block diagram illustrating a conventional audio signal processing apparatus for a television set. As shown therein, the apparatus includes a tuning unit 101 for selecting a channel required by a user from a plurality of channels in accordance with high frequency broadcasting signals received through an antenna ANT, a wave detecting unit 102 for receiving an output signal of the tuning unit 101 and restoring a video signal and an audio signal, an input signal selecting unit 103 for outputting to an image processing unit the video signal received from the wave detecting unit 102 and outputting one selected from the audio signal outputted from the wave detecting unit 102 and an external audio signal EAU.sub.in, a voice control unit 104 for adjusting a sound volume of the audio signal AU output from the input signal selection unit 103 and outputting a resultant signal to a speaker SP, and a microcomputer 105 for controlling respective blocks in accordance with a user selected signal received from a key input unit 106.
The operation of the conventional audio signal processing apparatus will now be described.
First, in case a user intends to watch an arial wave broadcasting, when a required broadcasting channel is input through the key input unit 106, the input signal is applied to the microcomputer 105 which in turn outputs the corresponding control signal to the tuning unit 101.
The tuning unit 101 selects one of a plurality of channels with high frequency broadcasting signals through the antenna ANT, that is, the channel which corresponds to the control signal applied thereto from the microcomputer 105 selected by the user, amplifies the television broadcasting signal of the corresponding channel to a predetermined level, and outputs the amplified signal. Then, the wave detecting unit 102 restores an original video signal and an audio signal from the signal outputted from the tuning unit 101.
The input signal selecting unit 103 transfers the video signal among those outputted from the wave detecting unit 102 to the image processing unit, and the audio signal AU is transferred to the voice control unit 104.
When there is required a playback of an external device through an additional connection line other than the case in which an aerial wave broadcasting is watched, that is, when peripheral devices such as a VCR, CD(compact disc) player, and LD(laser disc) player, are connected to the television set for their playback, a user may carry out the key operation of a corresponding function through the key input unit 106, and the microcomputer 105 recognizes the key operation to thereby apply a control signal CS1 corresponding thereto to the input signal selecting unit 103.
Then, the input signal selection unit 103 selects one from the audio signal or external audio signal EAU.sub.in outputted from the wave detecting unit 102 in accordance with the control signal CS1, and outputs the video signal and audio signal to the image processing unit and the voice control unit 104, respectively. The voice control unit 104 receives the audio signal AU outputted from the input signal selecting unit 103, and adjusts the received signal to a volume level required by the user, that is, a volume level in correspondence to the control signal CS2 outputted from the microcomputer 105 so as to be applied to the speaker SP.
However, the tone color adjusting technology of the conventional audio signal processing apparatus has a disadvantage in that a tone color compensation for respective frequencies is carried out using a preset value when selecting a tone color mode desired by a user after setting a compensation value in accordance with several tone color modes, thereby causing an inconvenience in use.
For example, when a user intends to listen to music while listening to news, the voice mode has to be manually converted to a music mode. That is, if there is no key input, the tone color is maintained without change.
Also, the tone color compensation is performed under the reference of average characteristics of respective major modes, so that different frequency characteristics have caused unnatural feelings. That is, such a tone color compensation has been stuck under a uniformed tone color.